Metal bar straightening machine



Nov. 15, 1949 F. J. KATz METAL BAR STRAIGHTENING MACHINE I5 Sheets-Sheet l Filed July 16,v 1945 5 `mm E uw! Nov. 15,l 1949 vF, J, KAT-L' A' I v 2,487,972

METAL -BAR STRAIGHTENING MACHINE www? AW NOV. 15, 1949 F J. KAj-Z 2,487,972

METAL BAR STRAIGHTENI'NG MAQHINE Filed July 16, 1945 s shee'ts-sheet s A TTOAZNYS Patented Nov. 15, 1949 METAL BAR STRAIGHTENING MACHINE Francis J. Katz, Forest Hills, N. Y., assignor to Hydropress, Incorporated, New York, N. Y., a'

corporation of Delaware Application July 16, 1945, Serial No. 605,271

Claims. 1

This invention relates to a Vmachine for straightening metal bars and particularly profiled or flanged bars of nonferrous metals such as aluminum, magnesium, their alloys, and the like.

Bars of intricate shape and large size are produced by extrusion methods and they become deformed for various reasons after extrusion so that they are buckled or` twisted either locally or throughout their entire length. It, therefore, 1s necessary to remove buckling and twists in the bars by some convenient method.

One of the objects of the present invention is to provide a machine having gripping heads with passages completely through the heads and grippers in said heads so that the bars can be passed completely through the machine and gripped between any desired points along the bar. The bar can be gripped and one of the heads moved relative to the other head, which has been previously anchored, so as to stretch the same beyond its yield point and thus remove any buckle that may be therein. If the bar has a twist therein, the present'machine provides means for twisting the same in the opposite direction beyond the yield point of the metal so as to untwist the bar. Considerable force is necessary in order to perform these operations. It is preferred that the force applying means be attached to the longitudlnally movable head in such a manner that said means is not rotatable as the head is rotated in an untwisting operation. This has proven to be quite difficult because of the high forces involved. In the preferred form of the straightening machine, hydraulic force is employed for the longitudinal stretching action and when such is used it has been found preferable not to rotate the hydraulic piston as the longitudinal force is applied to the stretching and detwisting head. One preferred form of thrust bearing comprises a divided radial roller bearing.

In one form of the invention, the hydraulic piston for stretching purposes is hollow for the passage of the bars therethrough. In another form of the invention, the hydraulic piston or pistons are parallel with a central tube and crosshead, with connecting bars for transmitting the force of the hydraulic means to the stretching and detwisting head.

Bars or shapes can be placed in the machine by passing them through the hollow gripping heads and then adjusting the position thereof so as to lock the desired portions of the bar between the two gripping heads. The bar then can be subjectedto a stretching and/or detwist- Fig. l is a broken longitudinal vertical section.

- Fig. 2 is a fragmentary enlarged plan view of the hydraulic piston operating means of Fig. l., -such section being taken approximately on the line 2-2 of Fig. 1 and showing the piston in an extended position.

Fig. 3 is a broken longitudinal elevation partially in section of a modified form of the invention.

Fig. 4 is a fragmentary plan view partly in section of the headstock and hydraulic cylinders of the modification shown in Fig. 3.

Fig. 5 is an end view of the tailstock along the line `5 5 of Fig. 1.

Fig. 6 is an enlarged fragmentary sectional view of the headstock of Fig. 3 showing details of the thrust bearing construction.

In Fig. l, frame I0 supports headstock II and tailstock I2, tailstock I2 being adjustably movable along the frame and being locked in place thereon by pivoted anchor I3 engaging locking stops I4 of the frame, lifting cylinder I5'being provided for raising anchor I3. Power means can I be provided for longitudinally moving the tailstock I2. Contained within tailstock I2 are gripping ngers I6, preferably there being four located 90 apart such as seen in Fig. 5. The gripping ngers I6 are guided along the cam surface I1 of body I8 of the tailstock, said ngers being operable by hydraulic pistons I9, said pistons obtaining operating forceV from oil pump 20 through any type of conventional control valve 2 I Headstock II has similar gripping ngers 22 operable by hydraulic pistons 23, said lingers being slidable on inclined surfaces 24 carried in headstock body 25. The rearward extension 246 of the headstock body has a worm wheel 21 attached thereto, aid wheel being driven by worm 28 from motor 9. plunger 30 has a suitable abutment means such as collar 3l mounted on the end thereof with a thrust-plate 32 co-operating with a plurality of radially mounted rollers. 33, said rollers being mounted in a suitable race. The axes of said rollers extend radially outwardly from the centerof rotation of the headstock. A second thrust plate is shown between rollers I3 and the rotatable gripping head 26. The rollers are prefer ably longitudinally sub-divided as seen in Fig. 8.

Hollow stretching force applying tube or` This is desirable because of the dierence in relativemotion between the outer and inner ends radially of the rollers and the contacting thrust plate surface, particularly when the bearing surface is extended in order to take the heavy loads involved. The stretching tube 3l extends into hydraulic cylinder 35 and serves as ahydraulic piston therein having a step 35 thereon, stumng boxes 31 and 38 being provided. Oil pressure can b'e supplied through valve 39 and passage 49 to operate the hydraulic piston in its stretching 1 operation or movement to the left as viewed in Fig. 1. A pump 4I and valve 42 provide oil presmanner similar to that shown in Patent No.

2,352,442 issued June 27, 1944. Mounted` on hy- Adraulic cylinder 35 are the return hydraulic pistons 43 (Fig. 2) which are connected by tie rods 44 with apertured cross head 46 fastened to the end of stretcher tube 30. Oil may be admitted to these pistons in order to return the headstock Ii to the right as seen in Fig. 1. It is evident that it is not absolutely necessary that there be more than one return piston 44 and that also there may be more than the two shown. An extension 14 of the crosshead 45 may be provided to co-operate with trough 15 to positively prevent rotation of the crosshead and hydraulic piston.

When it is desired to straighten a bar or shape, such shape is moved through the open passageways 41, 48, 41', and 49', it being possible to feed the same, for example, from the right to left (Fig. 1) through the tailstock. The tailstock and headstock are adjusted relative to each other so that the bar may be gripped at the desired points and the control mechanism is then operated so that the gripping lingers l and 22 iirmly grip the bar indicated in d'ot and dash lines at 45. Pressure may be applied to hydraulic cylinder 35 to stretch the bar if there is a buckle therein. If the bar has a twist, the motor 29 can be energized and the headstock body 25 and 26 rotated, stretching tube 30 not rotating therewith', the radial thrust bearing 33 allowing such rotation. If it is desired to stretch and twist at the same time, force also can be applied to hydraulic cylinder 35. The force may be applied afterthe stretching operation has taken place.

A second modication of the invention is shown in Figs. 3 and 4 wherein the hollow tube for applying 1ongitudma1 stretching force to the' headstock does not serve as the hydraulic piston. Referring to Fig. 49 is adjustably mounted on bed 50 and is xed in position thereon by means of anchor 5l engaging stops 52 in the bed 50, said tailstock having work gripping ngers 52 similar to Figs. 1 and 2. Headstock 54 has gripping lingers 55 operable by hydraulic pistons 55 similar to Figs. 1 and 2. Nonrotatable headstock housing 51 (Figs. 3 and 4) has connectors 58 (Fig. 4) extending to crosshead- 59. Crosshea'd 59 has two hydraulic pistons 69 mounted in hydraulic cylinders 6|, said pistons being connected to said crosshead at 62. Telescoping tube arrangement 63 may be provided centrally of the gripping head to serve as a guide for the bars being passed through the headstock. The housing 51 can be slidably mounted on the bed by means of feet similar to feet shown in Fig. 5 for the tailstock to assist in preventing rotation of the housing.

When it is desired to perform a stretching operation hydraulic pressure admitted into hysure for the hydraulic gripper cylinders 23 in a 'pins 54. The various hydraulic cylinders 5i and 85 are mounted on the frame so as to be nonrotatable with respect thereto, and may assist in holding housing 51 from rotation Aalthough normally all tendency of housing 51 to rotate will be prevented by the machine frame.

The headstock housing is provided with a worm wheel arrangement for turning gripping head 51 in a manner generally similar to that described in Figs. 1 and 2. .The worm wheel is seen at 98. A roller thrust bearing assembly has a plurality of longitudinally sub-divided rollers 59' and'10 between thrust bearing plates 1i and 12 similar to that described for Figs. 1 and 2, the axis of the rollers extendingradially froml the center of rotation of the gripping head. Rollers 59' and 10 are separate and may rotate at different speeds relative to each other. When nonrotatable headstock housing 51 is moved to the left, the thrust will be transmitted through ring 13 and radial split thrust rollers to the rotatable gripping head 61. The operation of the modiilcation of Figs.

3 and 4 for straightening bars is similar to that described for Figs. 1 and 2.: The hydraulic cylinders have no rotation and only a longitudinal rotion relative to their bearings and stumng xes.

It is to be understood that various modifications may be made to the embodimentsv shown without departing from the spirit of the invention or scope of the claims.

I claim:

1. In a machine for straightening bars of the character described, a frame, two gripping heads mounted on said frame, said heads having housings and having. aligned passageways therethrough for the passage of bars from end to end of and through the machine, bar gripping means in each of said heads for holding bars at spaced points, anchoring means on one of the gripping heads adjustably positioning said head on the frame relative to the second head, means connected to the second head for-.rotating the same, a hydraulic piston spaced from said second head and having one of said passageways aligned therewith, a non-rotatable hollow connecting tube extending between the housing of said second head and the hydraulic piston and aligned with said piston and housing passageways, abutment means on said tube, thrust bearing means between said abutment means and said rotatable second head allowing relative rotation between" the head and tube, and rotation preventing means connecting said frame and the hydraulic piston and tube.

2. In a machine for straightening bars of the character described, a frame, two gripping heads mounted on said frame, said heads having housings and having aligned ,passageways therethrough for the passage of bars from end to end of and through the machine, bar gripping means in each of said heads for holding bars at spaced points, anchoring means on one of the gripping heads adjustably positioning said head on the frame relative to the second head, means connected to the second head for rotating the same, a hydraulic piston spaced from said second head and having one of said passageways aligned housings and having aligned passageways therethrough for the passage of bars from end to end of and through the machine, bar gripping means in each of said heads for holding bars at spaced points, anchoring means on one of the gripping heads adustably positioning said head on the frame relative to the second head, means connected to the second head for rotating the same, a hydraulic piston spaced from said second head and having one of said passageways aligned therewith, a non-rotatable hollow connecting tube extending between the housing of said second head and the hydraulic piston and -aligned with said piston and housing passageways, abutment means on said tube, thrust bearing me'ans between said abutment means and said rotatable second head allowing relative rotation between the head and tube, rotation preventing means connecting said frame and the hydraulic piston and tube, and hydraulic motor means carried by said frame and connected with said rst mentioned hydraulic piston and tube operable to move said second head in a direction different than said rst mentioned hydraulic piston. i

4. In a machine for straightening bars of the character described, a frame, two gripping heads mounted on said frame, said heads having housings and having aligned passageways therethrough for the passage of bars from end to end of and through the machine, bar gripping means in each of said heads for holding bars at spaced points, anchoring means on one of the gripping heads adjustably positioning said head on the frame relative to the second head, means connected to the second head for rotating the same, a hydraulic piston spaced from said second head and having one of said passageways aligned therewith, a non-rotatable hollow connecting tube extending between the housing of said second head and the hydraulic piston and aligned with said piston and housing passageways, abutment means on said tube, thrust bearing means between said abutment means and Said rotatable 6 second head allowing relative rotation between the head and tube, rotation preventing means connecting said frame and the hydraulic piston and tube, a pair of hydraulic return motors mounted on either side of the cylinder for said rst mentioned hydraulic piston, and a crosshead connection between said return motors and said iirst mentioned hydraulic piston and tube.

5. In a machine for straightening bars of the character described, a. frame, two gripping heads mounted on said frame, said heads having housings and having aligned passageways therethrough for the passage of bars from end to end of and through the machine, bar gripping means in each of said heads for holding bars at spaced points, anchoring means on one of the gripping heads adjustably positioning said head 'on the frame relative to the second head, gripping head rotating means mounted on said second head including a motor, worm and worm wheel, a hydraulic piston spaced from said second head and having one of said passageways aligned therewith, a non-rotatable hollow connecting tube extending between the housing of said second head and the hydraulic piston and aligned with said piston and housing passageways, a ange connected with said tube, thrust bearing means between said flange and said rotatable second head allowing relative rotation between the head and tube, rotation preventing means connecting said frame and the hydraulic piston and tube, a pair of hydraulic return motors mounted on either side of the cylinder for said iirst mentioned hydraulic piston, and a cross head connection between said return motors and said iirst mentioned hydraulic piston and tube.

' FRANCIS J. KATZ.

REFERENCES CITED The following references are of Yrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,684,012 Dennison Sept. 11, 1928 2,164,343 Nighthart July 4, 1939 2,315,971 Lake Apr. 6, 1943 2,352,442 Loewy June 27,1944

FOREIGN PATENTS Number Country Date 490,125 Great Britain Aug. 9, 1938 552,677 Great Britain Apr. 20, 1943 OTHER REFERENCES Amer. Mach. pp. 116, 117, and 118, March 15, 1945.

.Certiiiateof 'Correction Patent No. 2,487,972 `ivmilxfos J. )Mrz November 15, 1949' It is hereby certified that error appears in the printed .specification of the above numbered patent requiring correction as follows; Y 4 A l Co1u mn 3, line 55, for Referring to 49 read Referring toAF'ig. 3i talstock 49;

and that the 'said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofce.

. Signed and sealed this 7th day of March, A. 1950.

THOMAS F. Mmm-rr,

Assistant Commissioner of Patente. 

